English

Debiasing and $t$-tests for synthetic control inference on average causal effects

Econometrics 2025-05-26 v9

Abstract

We propose a practical and robust method for making inferences on average treatment effects estimated by synthetic controls. We develop a KK-fold cross-fitting procedure for bias correction. To avoid the difficult estimation of the long-run variance, inference is based on a self-normalized tt-statistic, which has an asymptotically pivotal tt-distribution. Our tt-test is easy to implement, provably robust against misspecification, and valid with stationary and non-stationary data. It demonstrates an excellent small sample performance in application-based simulations and performs well relative to other methods. We illustrate the usefulness of the tt-test by revisiting the effect of carbon taxes on emissions.

Keywords

Cite

@article{arxiv.1812.10820,
  title  = {Debiasing and $t$-tests for synthetic control inference on average causal effects},
  author = {Victor Chernozhukov and Kaspar Wuthrich and Yinchu Zhu},
  journal= {arXiv preprint arXiv:1812.10820},
  year   = {2025}
}
R2 v1 2026-06-23T06:57:32.265Z